We developed a two-dimensional combustion model to predict the transport phenomena in semicoke burning at the surface in a CDQ (Coke Dry Quencher) pre-chamber and blast furnace. Experiments and numerical simulation were carried out to analyze the transport phenomena in a spherical semicoke particle burning in a laminar gas stream. The model assumes that the semicoke particle is a packed bed of micro semicoke particles, and the combustion of fixed carbon is calculated as the char. Coke pyrolysis is also estimated involving the deposition and decomposition of tar and the combustion of VM (volatile matter). Gas flow in the packed bed and gas phase around the particle are calculated by Darcy's equation and Navier-Stokes equation, respectively. The effect of heterogeneous and homogeneous reactions of the single semicoke particle on its property is calculated by the control volume method (CVM). The analysis shows that the combustion of the semicoke particle is governed by boundary layer diffusion and the homogenous reactions prevent the semicoke particle from consumption by heterogeneous reactions.